Accelerator of vulcanization



4;! mixture 7 Patented May 12, 1931 it warran "Sm-Es PATENT orri -g JAN rr errnnag or AKRON, 01110, nssrenonro THE GOODYEAR TIRE annimnn con:-

'EPANY, or Arman, cnro, ecoaronarron or onro ACCELERATOR or vunoANIzA'rIon N0 Drawing. Original application fi led-December 1c, 1927, Serial No. 239,267, and in Great Britain ,n gust 27,1928. iDivided and this application fi'1ec1November 26, 1928. Serial No. 322,086.

My invention relates to thetreatment of I 7 rubber and it has particular relation tothe provision of a new class-ofmaterialswhich, when incorporated in rubber compounds, materially accelerate the rate of vulcanization thereof. V y I V More specifically, the invention hasfor one o'f its objects the provision of an accelerator v to Heretofore, it has been observedzthat certain sulphur contammg orgamc' compounds;

for example thiocarbamates and xanthogen- The reaction product of 2rbenzoyl r4 -nitro phenyl sulphur bromide with sodium diethyl dithio carbamate, cited above; is a typical substance of this class This material may be prepared as follows Y t vDissolve 2-benzoyl nitro phenyl sulphur bromide (16.9 parts) andtsodium diethyldithiocarbamate (8.5 parts) in dry benzol. v 7

Heat themixture tothe boiling lpoint of the solvent under a reflux condenserfor a period of approximately one hour and then distill off the volatile constituents on a steam bath.

water to remove any traces of benzol "that may remain after the distillationupon the The resid-ueobtained is poured into boiling water bath. The residueis obtained from the water solution in the form of a ca-ked -mass which readily dissolves in hot water.

The mechanics of the reaction taking place may be represented by the following structural formula:

oooim oiN 7 3o vates,when incorporated rubber comound, greatly accelerate the rate .of vulcanization of the latter. 7 This invention consists in the discoverythat certain-salts ofsulphur containing compounds for example the sodi- 35 um salt of gdiethyl 'dithiocarbamate or the sodium salt of mercaptobenzothiazole,may be caused to react with such organic halogen sulfides as Q-benzoyl d-nitro phenyl sulphur bromide, to producesubstances having excel- 40 lent properties as accelerators ofthe rate of, vulcanization of rubber These compounds w'Ihe reaction product of fl-benzoyl-nitrophenyl sulphur bromide with the sodium salt of mercaptobenzothiazole is another; comfpoundof-this same general class whichfis an excellent accelerator of vulcanization. This material may be prepared ,as follows:

7 a .8 Dissolve the sodium salt of n ercaptobenzo Y 'thiazole (8,85 parts) inboiling,alcoholand; r

allow thesolution to cool untilit islulre warm.

Then add to the solution 17 parts of 2-benz0yl t-nitro phenyl sulphur bromide. The solutionthus obtained assumes a dar k-lred -eolor for a short time color, however, each disappears and a yellow precipitate is formed. The solution containinglthe precipitateis boiled for a'period of'one hour and is then cooled and filtered. The filtrate may be washed with water and then air dried. If it is desired to obtain the product in a purified form, the washed filtrate may be recrystalized from benzol.

The same material may be obtained by the interaction of the basic materials in the presence of anhydrous aluminum chloride. According to this method, Q-benzoyl -nitro phenyl sulphur bromide (85 parts) are suspended in dry carbon bisulphide. To this suspension are added 42 parts of mercaptobenzothiazole and 45 parts of aluminum chloride (AlOl No reaction occurs at room temperature. However, if the mixture is refluxed for a period of two hours or more, hydrogen bromide (HBR) begins to be evolved. r

Preferably, the mixture is permitted to remain under the reflux condenser for. a period of several hours (12 or 16 hours). The reaction product is then heated in a steam bath in order to drive 0a the volatile components of the mixture- The residue is poured upon ice water, filtered, washed with water anddried. This product is then recrystallized from benzol and is obtained therefrom in the form of colorless needles having a melting pointbetween 122 and 128 C. The yield obtained is practically quantitative.

The reaction of Q-benzoyl l-nitro phenyl sulphur bromide with the sodium salt of mercaptobenzothiazole may be represented by the following structural formula:

CO CoH S-Br COCsH; V /O-SNa N N My invention of course is not limited to the Parts Extracted rubber 100 Zinc oxide 5 Sulphur 3 Stearic acid 1.5 Accelerator .5

Z-beuzoyl 1,-uitr0 phenyl sulphur bromide and mercdptobenzothiazole Load in Tensile 2 we zeta a e.

elong. g

2-beuz0yl l -uitro phenyl sulphur bromide and sodium (Methyl dithz'ocarbamate From the preceding table it will be evident that the compounds included within the scope of the invention are rapid accelerators. They also result in a product having a high degree of tensile strength and elasticity.

Although I have described in detail only the preferred embodiments of the invention, it will be apparent to those skilled in the art that it is not so limited but that various minor modifications may be made therein without S MI) departing from the spirit of the invention or from the scope of the appended claims.

WVhat I claim is:

1. A method of treating rubber which comv prises vulcanizing it in the presence of the reaction product of a benzoyl nitro phenyl sulphur halide and an alkali salt of a mercaptoarylthiazole. k

2. A method of treating rubber which comprises vulcanizing it in the presence of a material having the following structural formula:

. NO: in which R represents a mercaptobenzothiazole radical. 1 r 3. A rubber product that has been vulcanized in the presence of a material having the 1 following structural formula in which R represents a mercaptothiazole radical.

4. A method of treating rubber which comprises subjecting it to vulcanization in the presence of a reaction product of a benzoyl nitro phenyl sulphur halide and an alkali salt of a mercaptobenzothiazole.

5. A method of treating rubber which comprises subjecting it to vulcanization in the presence of a material formed by the inter action of Q-benzoyl 4z-IlltI'O phenyl sulphur bromide and an alkali salt of a mercaptobenzothiazole. I I

6. A method of treating rubber which comprises subjecting it to vulcanization in the presence of a material having the following structural formula:

in which R represents a benzoyl nitro phenyl 39 sulphide group, and R represents a benzene group.

7. A rubber product that has been vulcanized in the presence of a reaction product of a benzoyl nitro phenyl sulphur halide and a mercaptobenzothiazole.

8. A rubber product that has been vulcanized in the presence of a material having the following structural formula:

- in which R represents a benzoyl nitro phenyl sulphide group, and R represents a benzene group.

In witness whereof, I have hereunto signed my name.

Si ned at Akron, in the county of Summit and state of Ohio, U. s. A., this 23rd day of November, 1928. Y

Y JAN TEPPEMA; 

